A process of compressing video data to store or send the video data is required due to its large size. Typically, when video data is encoded, the video data is encoded by performing intra prediction or inter prediction, transformation, quantization, entropy coding, or the like on each picture of the video data in units of blocks.
Particularly, in the intra prediction, prediction from an adjacent block is performed using spatial duplication in order to reduce duplication of data in a video. For example, in existing intra prediction of H.264/AVC, extrapolation is performed using nine modes. The intra prediction has a drawback in that accurate prediction is difficult as a pixel to be predicted is away from a reference pixel. Particularly, use of existing intra prediction in representing texture degrades accuracy of the prediction.
Further, in the intra prediction or the inter-frame prediction, distortion between an original video and a restored video may occur or may degrade accuracy of subsequent intra prediction or inter-frame prediction.